Find out the oxidation number of chlorine in the following compounds and arrange them in increasing order of oxidation number of chlorine.
`NaClO_(4), NaClO_(3), NaClO, KClO_(2), Cl_(2)O_(7), ClO_(3), Cl_(2)O, NaCl, Cl_(2), ClO_(2)`.
Which oxidation state is not present in any of the above compounds?`

Explanation

Suppose that the oxidation number of chlorine in these compounds be x
O.N. of Cl in `NaClO_(4)" ":." "+1+x+4(-=2)=0" or",x=+7`
O.N of Cl in `NaClO_(3)" ":." "+1+x+3(-2)=0" or", x=+5`
O.N. of Cl in `NaClO" ":." "+1+x+1(-2)=0" or",x=+1`
O.n of Cl in `KClO_(2)" " ,." "+1+x+2(-2)=0" or",x=+3`
O.N. of Cl in `Cl_(2)O_(7)" ":." "+2x+7(-2)=0" or",x=+7`
O.N. of Cl in `ClO_(3)" ":." "x+3(-2)=0" or",x=+1`
O.N. of Cl in `NaCl" ":." "+1+x=0" or",x=-1`
O.N. of Cl in `Cl_(2)" ":." "2x=0" or",x=0`
O.N. of Cl in `ClO_(2)" ":." "x+2(-2)=0" or", x=+4`
None of these compounds have an oxidation number of +2.
Increasing order of oxidation number of chlorine is : `-1,0,+1,+3,+4,+5,+6,+7`
Therefore, the increasing order of oxidation number of Cl in compounds is
`NaCl lt Cl_(2) lt NaClO lt KClO_(2) lt ClO_(2) lt NaClO_(3) lt ClO_(3) lt Cl_(2)O_(7)`